Standard definitions of the Lopatinski condition and the uniform Lopatinski condition for initial boundary value problems for linear constant coefficient hyperbolic systems were given by Kreiss [1]}. For symmetric hyperbolic systems having the 1-shock property one can use equivalent definitions. They were introduced in [2]} by using ideas of the normal modes analysis in [3]} for MHD shock waves.
Following [2]}, we now give them for our problem (REF )–(REF ). For the reader's convenience, in Appendix  we give the derivation of the Lopatinski determinant for symmetric hyperbolic systems with the 1-shock property (some points of the analysis are described in Appendix  even in more detail than in [2]}).
